Comment 29 for bug 89746

I have done a more comprehensive test of boot parameters too see the behavior of my system. These were all done running Gutsy Tribe 4 with linux-image-2.6.22-9-generic version 2.6.22-9.25 on amd64 architecture. My HP dv6000 series laptop has a dual-core AMD Turion64 x2. I'm running the proprietary nvidia driver.

No special boot params: hangs during "Loading hardware drivers." Does not respond to ctl-alt-del.
noapic: boots up properly. top shows 70% of combined CPU usage in hard interrupt state. After a minute or two, kernel says "disabling IRQ #7." According to /proc/interrupts, IRQ 7 is for ehci_hcd:usb1.
noapic noirqdebug: boots up properly. top shows 70% of combined CPU usage in hard interrupt state. In /proc/interrupts, interrupts appear unbalanced to CPUs. Also, appears that the 70% interrupts are being caused by ehci_hcd.
acpi=noirq: problems loading X. Screen turns black and does not progress further. Still responds to ctl-alt-del and reboots the box.
acpi=off: same symptoms as acpi=noirq.
pci=noacpi: same symptoms as acpi=noirq.
nmi_watchdog=0: same symptoms as using no special boot params.
nmi_watchdog=2: same symptoms as using no special boot params.
maxcpus=1: boots and appears to work well (only with 1 core). However, shutdown appears to hang. Once it hung with "System is restarting, please wait..." on the screen. Another time it hung after printing "Running local boot scripts (/etc/rc.local) [OK]".

Currently I am run with "noapic noirqdebug" for normal usage and I don't see any hangs or other issues besides the fact that performance is poor.